1. Field of the Invention
The present invention relates to fingerprint and palm print capturing devices and, more particularly, to a device and method for touchlessly obtaining fingerprints and palm prints using a plurality of cameras and lights to quickly and efficiently capture all such biometric information.
2. Description of Related Art
Fingerprints are unique to each individual person and, as such, have been a cornerstone for identification, recognition and authentication of people. Since the pattern of friction ridges is invariant over a person's lifetime aside from any deforming injuries, fingerprints are especially useful for forensic investigations, background checks and security. In addition to one's fingerprint, there is a great deal of distinguishing information contained in the friction ridges of the palm, as well as the sides and tips of the fingers. Hand geometry, the shapes and relative proportions of parts of the hand, also contains distinguishing information.
Today, fingerprints are typically acquired using ink and cards, “live-scan” inkless scanners or optical sensors. Examples of live-scan technology are disclosed in U.S. Pat. No. 6,983,062 to Smith and U.S. Pat. No. 6,628,813 to Scott. An example of an optical sensor is disclosed in U.S. Pat. No. 6,956,608 to Shapiro et al. The ink, live-scan and optical methods usually require trained operators to be present to ensure that the prints have been captured properly, and the process can take up to five or ten minutes to capture a full set of prints. Also, they require rolling of the fingers from nail to nail to capture the friction ridges on the sides of the fingers. These methods are subject to human error in the rolling, as well as sensitivity to contamination, moisture, or excessive dryness. Different amounts of pressure in the rolling can also result in unwanted variation between different prints of the same finger. Some live-scan and optical devices capture only fingerprints, but others will also capture palm prints.
There has been some recent development in touchless fingerprint capturing. Presently, these inventions are directed toward capturing one fingerprint at a time, excluding the tips. Two devices which use cameras and lights to capture fingerprints are disclosed in U.S. Patent Application Publications 2005/017784 to Merbach et al. and 2006/0045316 to Hauke et al. These devices use several light sources to maximize contrast and avoid shadows in the images. Merbach discloses the use of different colors of light in order to improve contrast. The lights and cameras are used in conjunction with each other to sequentially capture images of different parts of the finger from different directions. A method for piecing together several images to create a continuous model of the fingerprint is also incorporated. Hauke further discloses projecting the three-dimensional model surface of the finger onto a plane.
Generally, the more information which can be extracted from a hand, the more effective and useful the prints obtained will be for background checks, forensic investigations, security, etc. Also, fingerprint and palm print technology is becoming particularly necessary in airports and border patrols to prevent terrorism and other criminal activity. In all of these contexts, the prints captured are often compared with those in large databases. Thus, there is an escalating need for fast, accurate and complete fingerprint and palm print capturing to serve these purposes. However, the presently available touchless technology inefficiently requires fingerprints to be captured one at a time, and fails to capture the majority of the biometric information on the hand as a whole. Furthermore, the prior art capture devices introduce operator error or incorrect data capture. For example, because only one finger is scanned at a time, it may be the case that the wrong finger is inserted for scanning purposes, either unintentionally or deliberately. Therefore, the resultant captured fingerprint data may be incorrect with respect to the intended digital representation of a particular finger. Additionally, the prior art captures only the front and sides of the distal ends of the fingers and thumb. Information contained on the more proximal surfaces of the fingers, the tips of the fingers, and the palm is not captured by the devices disclosed in Merbach and Hauke. Such additional information is very useful for identification, recognition and authentication and, as such, there is a need for systems and methods which can capture all such information accurately and efficiently.